I wish I could say the same good things about the tremol-no, sa5150. But the truth is that I'm quite disappointed with it. Maybe I'm quite a dumb when it comes to mechanical guitar parts, but that's my experience.
Best part is installation, it was so easy that even I could do it. And at first it looked like it worked well enough, but after a few rehearsals and gigs I began to realize its shortcomings. The locking mechanism is too simple, cheap I would say. It's just one (dive-only mode) or two (hardtail mode) little screws pressing against a metal bar inside a metal shaft linking the bridge with the claw. Turn the screws clockwise, they push onto the metal bar creating friction, thus preventing any play and locking the tremolo. That IS the locking mechanism, friction.
As you can imagine, it doesn't take much strength to unlock it. If you forget you are locked and reach for the tremolo bar, even a soft vibrato will unlock it. Not ideal, if you dropped your tuning all strings go out of tune, you have to tune up and lock again, but if this were the only problem... This is with the hardtail mode lock, which is provided by two screws. The dive-only mode is locked by only ONE screw, and a really slippery one at that. Let's say the lock is not very stable, you don't even have to touch the tremolo bar, sometimes it unlocks alone, sometimes just by looking at it, sometimes it won't stay in place, jumping around the tremolo cavity up and down the locking bar, and it takes a few tries to get a somewhat stable grip. All these are mechanical problems, I don't think it's my fault, because you only have to turn screws, and they don't hold up well enough. There a no grooves for the screws to hold up in place, they push onto bare plain metal, and create friction with their blunt tip.
Now, tuning stability is not great. In this case I might not have tuned the installation as well as I should, I don't know. I just have to say that locking the tremolo will move your tuning a few cents. And if you drop your low e string, the others go a bit sharp. Not too bad for power chords, but the point of the tremolo-no was easy drop tunings with no tuning problems.
Finally, the worst part. The locking screws. When the bridge is locked, they are relatively stable screwed to the bar. But when you unlock, if you make too many turns they WILL fall to the ground. AND if you don't lock them after playing, they are loose and will turn alone until they fall to the ground. I have found a screw on the ground TWICE, that's why they must include a spare one in the package. But eventually you won't notice and forget one of them at a gig, and run out of screws. Will I be able to get a replacement?
I guess it's pretty hard to imagine how it works just by reading my post, but when you have it in your hands you see how flimsy it is.
